I have a 2005 Ford F-350 service truck,,it has a 5.4L 3V gas engine and has 159869 miles on it. No codes!! Truck starts,,idle races up to 900-1000 rpms and begins to drop to 5-600,,it will just bog or CHAAAAWWWWW if you touch the throttle,,let off and it will most times stall. It is unable to move the truck,,,,start it up and for a slit second it acts as it will rev up but fails and just goes CHAAAAAWWWWW out the intake. I just dont know where to turn on this deal,,Richie 1-774-406-7289 or a5cos@aol.com. Thanks for any advice.

 

Hello 1290pine and welcome to FTE.

That generally indicates that your cam timing is off. I would bet that you probably need to replace the timing chains, chain guides and tensioners on the engine.

 

Dont be scared to jump into the timing on theses engines.. I had a cobra and its the 32v mod motor.. i had it apart for the heads and blower setup i was running.. GET GENUINE FORD PARTS!!!! Dont go cheap on keepers, guides, and chains... i ran cheep ones and i got what i paid for.. they shredded and trashed my motor.. so I did it again.. the right way... take your time and its not bad at all.. x2 on the timing.. also unplug the MAF and see how it acts.. also clean it with the propper MAF cleaner and see if that helps any

 

I will try, I take it these are non interference engines?

 

Fuel pump? check psi.

 

Good question. I have never heard of a valve hitting a piston so I guess if is a noninterference engine.

 

beleive it or not,,had to take to ford,,replaced bothe cats and it runs! WTF

 

Must have been an issue with the engine to cause the cats to go bad! Did they say how they thought it happened? Usually running rich with too much fuel in the exhaust..


Dick

 

No, I would never had guesed this,,2 new cats and the truck runs fine. Crazy.

 

It will run fine for a while until they over heat again if the orig problem is still happening.
Check or change o2 sensors at a minimum. They last maybe 100k max.

Dick

 

I will change them.